Multiple Input Multiple Output (MIMO) communication is supported in wireless communications standards such as 3rd Generation Partnership Project (3GPP), Evolved High-Speed Packet Access (HSPA+), Long Term Evolution (LTE) and Worldwide Interoperability for Microwave Access (WiMAX).
A MIMO system utilizes multiple transmit and receive antennas for communication to significantly increase the throughput of the system. In a MIMO communication system, the data payload may be partitioned into a plurality of blocks that are encoded and decoded independently. For example, in the Downlink component of the HSPA+ standard, an evolution of High-Speed Downlink Packet Access (HSDPA), MIMO communication is performed over two separately encoded blocks of data or ‘streams.’ Separately encoded blocks of data are also employed in LTE and The Institute of Electrical and Electronics Engineers (IEEE) 802.11 family of standards.
Successive Interference Cancellation (SIC), an optimal technique for processing multiple streams at the receiver, decodes streams of data one by one. Upon successful decoding of a stream, effects of the decoded stream are subtracted from the received composite signal to eliminate the interference of the decoded stream on the remaining streams. Therefore, the remaining streams may have a higher likelihood of successful decoding. The decoded signal may be reconstructed by re-encoding and re-modulating before subtraction from the received composite signal.
The order in which the steams are decoded has an impact on the SIC performance. In addition, scaling the reconstructed signal appropriately before interference cancellation may improve system performance. Therefore, there is a need in the art for dynamically determining the decoding order and reconstruction weights in a successive interference cancellation receiver in MIMO systems.